Due to the increasingly high occurrence of tampering with pharmaceutical containers and the like, particularly before purchase by the consumer, many attempts in recent years have been directed towards producing tamper-proof closures or caps which would signal or alert potential consumers that tampering or unauthorized access of the containers has transpired. The common use of incorporating tear-away strip caps have been increasingly employed; these caps, when opened, conveniently leave broken cap strips, thus very clearly alerting a customer to the fact that tampering of the closure has occurred.
It is known to weld or seal a portion of a cap directly to a part of a cap-abuttment or cap-seating flange or neck of the container to seal the cap to the container. When the cap is then removed, a portion below or adjacent the sealed portion may remain with the container while the remainder of the cap is removed. This allows for the cap, upon a hand turning force exerted thereon, to break off via for example a weakened portion, so that a portion of the cap becomes an integral non-removable portion of the container. For example, U.S. Pat. Nos. 3,525,454 to Fredericksen; 3,788,509 to Keeler; 3,851,783 to Braginetz; 4,011,961 to Widen et al; 4,207,988 to Provty et al; and 4,494,663 to Bertard et al all disclose tamper-proof caps or closures which are heat sealed or ultrasonically welded directly to the container flange or neck.
However, some of these above-mentioned patents require weld rings between the cap and the container to ensure a proper sealing of the cap and container when the heat sealing or ultrasonic generating apparatus are placed thereabout, thereby increasing the time and cost of manufacturing the sealed container. Furthermore, welding of the cap may only be completed in the internal regions where the cap abuts the container, thereby allowing the premature dislodgement of the cap from the container. Additionally, all of these prior art proposals require the necessity of large cumbersome apparatus to accomplish sealing of the cap to container, thereby providing slow and expensive production of the capped containers.
In the aforementioned Keeler USP, a spot welder is repeatedly reciprocated (see FIG. 3); this is not a practical solution, as it is too slow for commercial production. The aforementioned patents do not specify with sufficient particularity how to precisely obtain their seals, and furthermore such patents all relate to non-screw closures of particular and intricate construction which cannot be used in conjunction with the typical "top-hat" style screw cap. The same is true of the construction of the Fredericksen U.S. Pat. No. 3,525,454.
No tamper-proof screw cap or closure of the "top-hat" variety for use on pharmaceutical containers has previously been available which can be quickly and inexpensively sealed to a container. In addition, there is a great need for a tamper-proof cap of this type which can be sealed to a container flange wherein a large majority of the cap flange is ultrasonically or heat sealed to container flange with ease, simple equipment, quickly, inexpensively and with expediency while assuring a permanent and effective seal.